John Boiles, he of the iPod-controlled RC car, also produced this sweet wirelessly controlled light dimmer, which he demonstrates in this video, controlling different sets of X-mas lights by shaking his iPod. See it work around 1:40, then be sure to check out the dance party at 2:40. The iPod is enclosed in the “law book” prop everyone is shaking around, together with their booties, while they rock out to vintage Bon Jovi, et. al.
iPod-accelerometer-controlled dance floor lights